278 PATHOLOGY OF NUTRITION. 



In fatty infiltration of the heart the muscle-fibres are not 

 necessarily affected, and consequently there is little or no func- 

 tional impairment, though by interfering with the local blood- 

 supply the condition may become one of fatty degeneration. 



Fatty degeneration is caused by local interference with the 

 blood-supply, anaemias, and high temperature. Poisons such 

 as mercury, arsenic, lead, phosphorus, ether, chloroform, and, 

 of still greater interest clinically, the toxins of micro-organ- 

 isms are frequent causes. The cell is shrunken, not swollen, 

 its outline irregular, and the nucleus destroyed. The oil-drops 

 are smaller and do not tend to run together as in fatty infiltra- 

 tion, appearing in the cell first as small shining granules near 

 the nucleus. There is a gradual liquefaction of the cells, end- 

 ing in their death. 



Any tissue in the body, with the exception, in the blood, 

 of the red globules, may be affected ; but the parenchyma- 

 cells of the liver, kidney, heart, and central nervous system 

 most often the interstitial tissue being possibly later affected. 



The fat-drops are distinguished chemically by their insolu- 

 bility in acetic acid and weak solutions of sodium and potas- 

 sium hydroxide ; and by their solubility in alcohol, ether, and 

 chloroform, and by staining black with osmic acid. Fine needles 

 in rosettes, sheaves of margaric acid, and rhombic plates of 

 cholesterin are often found. 



The organ affected is pale yellow or mottled, very anaemic, 

 and feels greasy and soft. 



Amyloid, lardaceous, or waxy degeneration is a very fre- 

 quent retrograde change and next to fatty degeneration is the 

 most common. It signifies the presence in the tissue of a 

 colorless, firm, translucent, homogeneous, inelastic material of 

 about the consistency of wax or solidified lard, to which, on 

 account of its behavior toward iodine, the term " starch-like" 

 has been given ; though we now know that it is not a carbo- 

 hydrate, but a nitrogenous compound (Fig. 113). If a solu- 

 tion of iodine and iodide of potassum (LugoPs) be applied to the 

 freshly cut surface of an affected area, there results a mahogany- 

 brown coloring, the surrounding normal tissue being stained a 

 canary-yellow. The addition of a 1 per cent, solution of sulphu- 

 ric acid gives the amyloid material a bluish color. For micro- 

 scopical sections a much more satisfactory staining reaction is 



